Late Pleistocene fishes of the Tennessee River Basin: an analysis of a late Pleistocene freshwater fish fauna from Bell Cave (site ACb-2) in Colbert County, Alabama, USA Stephen J. Jacquemin1, Jun A. Ebersole2, William C. Dickinson3 and Charles N. Ciampaglio1 1 Lake Campus, Wright State University, Celina, OH, United States 2 Collections Department, McWane Science Center, Birmingham, AL, United States 3 412 Nottingham Court, Maryville, TN, United States ABSTRACT The Tennessee River Basin is considered one of the most important regions for freshwater biodiversity anywhere on the globe. The Tennessee River Basin currently includes populations of at least half of the described contemporary diversity of extant North American freshwater fishes, crayfish, mussel, and gastropod species. However, comparatively little is known about the biodiversity of this basin from the Pleistocene Epoch, particularly the late Pleistocene (∼10,000 to 30,000 years B.P.) leading to modern Holocene fish diversity patterns. The objective of this study was to describe the fish assemblages of the Tennessee River Basin from the late Pleistocene using a series of faunas from locales throughout the basin documented from published literature, unpublished reports, and an undocumented fauna from Bell Cave (site ACb-2, Colbert County, AL). Herein we discuss 41 unequivocal taxa from 10 late Pleistocene localities within the basin and include a systematic discussion of 11 families, 19 genera, and 24 identifiable species (28 unequivocal taxa) specific to the Bell Cave locality. Among the described fauna are several extirpated (e.g., Northern Pike Esox lucius, Northern Submitted 9 October 2015 Accepted 11 January 2016 Madtom Noturus stigmosus) and a single extinct (Harelip Sucker Moxostoma lacerum) Published 2 February 2016 taxa that suggest a combination of late Pleistocene displacement events coupled with Corresponding author more recent changes in habitat that have resulted in modern basin diversity patterns. Stephen J. Jacquemin, The Bell Cave locality represents one of the most intact Pleistocene freshwater fish [email protected] deposits anywhere in North America. Significant preservational, taphonomic, sampling, Academic editor and identification biases preclude the identification of additional taxa. Overall, this María Ángeles Esteban study provides a detailed look into paleo-river ecology, as well as freshwater fish diversity Additional Information and and distribution leading up to the contemporary biodiversity patterns of the Tennessee Declarations can be found on River Basin and Mississippi River Basin as a whole. page 34 DOI 10.7717/peerj.1648 Subjects Aquaculture, Fisheries and Fish Science, Biogeography, Ecology, Evolutionary Studies, Copyright Paleontology 2016 Jacquemin et al. Keywords Long term assemblage change, North America, Freshwater fish biogeography Distributed under Creative Commons CC-BY 4.0 OPEN ACCESS How to cite this article Jacquemin et al. (2016), Late Pleistocene fishes of the Tennessee River Basin: an analysis of a late Pleistocene freshwater fish fauna from Bell Cave (site ACb-2) in Colbert County, Alabama, USA. PeerJ 4:e1648; DOI 10.7717/peerj.1648 INTRODUCTION Over the past 70 years, several comprehensive synopses have been published on North American Quaternary freshwater fishes (see Miller, 1959; Miller, 1965; Uyeno & Miller, 1963), with the last major works written by Smith (1981) and Cavender (1986). Absent from these reviews, however, are reports of the Tennessee River Basin as a whole or any reports of late Pleistocene fish remains from many southeastern localities (in particular, sites within Alabama and Tennessee). This has important implications given that the southeastern United States is one of the largest hotspots of freshwater biodiversity, with the modern Tennessee River Basin being home to approximately 240 fish species (Appendix S2; National Water Quality Assessment Program, 2015; Etnier & Starnes, 1993; Boschung & Mayden, 2004; Page & Burr, 2011). The Tennessee River Basin encompasses an aerial extent that covers more than 105,000 km2 and stretches across seven states: Alabama, Georgia, Kentucky, Mississippi, North Carolina, Tennessee, and Virginia (Etnier & Starnes, 1993; Fig. 1). The diversity of fishes and habitats in this geographic area warrants additional study of the fossil record to provide a better understanding of the region's paleoecology, biogeography, and evolutionary history. The objective of this study was to concatenate and add to prior research to provide a more comprehensive understanding of the Pleistocene ichthyofaunal record of the Tennessee River Basin. Known Pleistocene sites with fish occurrences from the Tennessee River Basin include sites ACb-2 (reported herein), ACb-3 (4 unequivocal taxa; identified by authors), ACb-5 (1 taxon; identified by authors); and Little Bear Cave (unidentified fish taxa; Womochel & Barnett, 1980) in Colbert County, AL; Dust Cave (7 unequivocal fish taxa; Walker, 1998) in Lauderdale County, AL; Appalachian Caverns (5 unequivocal taxa; identified by authors), Baker Bluff Cave (14 unequivocal fish taxa; Guilday et al., 1978), Beartown Cave (1 taxon; identified by authors), and Guy Wilson Cave (3 unequivocal taxa; identified by authors) in Sullivan County, TN; Cheek Bend Cave (25 unequivocal fish taxa; Dickinson, 1986) in Maury County, TN; and Saltville (1 taxon; McDonald & Bartlett, 1983; 3 additional unequivocal taxa; Dickinson, 1986) in Smythe County,VA (Fig. 1). While these sites do represent numerous locales across the Tennessee River Basin, none of the described sites include the mainstem of the Tennessee River and only two sites (Baker Bluff Cave and Cheek Bend Cave) had reported more than a few taxa. The relatively low number of taxa and lack of mainstem habitat signifies a need for additional samples to better assess the diversity of the region during this time period. During the summers of 1984 and 1987, personnel from the former Red Mountain Museum (Birmingham, AL) and the Alabama Museum of Natural History (Tuscaloosa) conducted extensive excavations within Bell Cave (site ACb-2; Colbert County, Alabama), located along the south bank of the lower reaches of the mainstem Tennessee River. The cave's locale along the mainstem Tennessee River and position within the basin make it potentially one of the most significant North American locations for documenting Pleistocene freshwater fish biodiversity. To date, excavations of Bell Cave have resulted in the recovery of nearly 4,000 cataloged lots of late Pleistocene faunal remains from four Jacquemin et al. (2016), PeerJ, DOI 10.7717/peerj.1648 2/40 Figure 1 Map of Tennessee River Basin. Shaded areas show the extent of the Basin. Listed late Pleistocene localities are as follows: 1, Bell Cave (site ACb-2), Colbert County, AL.; 2, site ACb-3, Colbert County, AL; 3, site ACb-5, Colbert County, AL; 4, Appalachian Caverns, Sullivan County, TN; 5, Baker Bluff Cave, Sullivan County, TN; 6, Beartown Cave, Sullivan County, TN; 7, Cheek Bend Cave, Maury County, TN; 8, Dust Cave, Lauderdale County, AL; 9, Guy Wilson Cave, Sullivan County, TN; 10, Saltville, Smythe County, VA. distinct stratigraphic levels within the cave. However, to this point, no formal description of the Bell Cave ichthyofauna has been undertaken. Formal descriptions of other faunas captured from Bell Cave have included amphibians and reptiles (Holman, Bell & Lamb, 1990; Holman, 1995; Jasinski, 2013), birds (Parmalee, 1992), and mammals ranging in size from rodents to extinct megafauna (Bell, 1985; Churcher et al., 1989; Martin & Prince, 1990; Parmalee & Graham, 2002; McDonald, 2003; Ruez, 2008; Ebersole & Ebersole, 2011). Specific to the fishes, however, only brief mention have appeared in the literature and only as ancillary information. Churcher et al. (1989: 1214), for example, mentioned at least ``20 fish'' taxa (based on preliminary identifications by WC Dickinson) among the Bell Cave faunas while Parmalee & Graham (2002) simply reported the presence of ``fish'' within the cave. Parmalee (1992) was the first to mention specific fish taxa from Bell Cave, noting the presence of Sturgeon Acipenser, Drum Aplodinotus, Catfish Ictalurus, and Redhorse Moxostoma, but did not cite any cataloged specimens or provide any systematic material or comparisons. Formal descriptions of the fishes from Bell Cave will hopefully help fill a gap in our understanding of regional diversity during this time period. Jacquemin et al. (2016), PeerJ, DOI 10.7717/peerj.1648 3/40 The purpose of this study is to expand our understanding of late Pleistocene fish diversity in the Tennessee River basin by closely examining existing faunal lists as well as describing the 235 cataloged lots of Bell Cave fish material to develop our understanding of the fish assemblages during this time period. These fish remains represent one of the largest Pleistocene fish faunas reported from North America, the largest from the Tennessee River Basin, and the first published from the state of Alabama. The overarching comparison of the Bell Cave fauna to others within the Tennessee River Basin not only serves to fill a regional gap in terms of knowledge of late Pleistocene fish occurrences, but also provides valuable insights into the biogeography and paleoecology of these fish taxa within the basin during the late Pleistocene. MATERIALS & METHODS Late Pleistocene faunal lists from localities located within the boundaries of the Tennessee River Basin were recorded based on both